More than 4,000 people have been killed in Syria since Sept. 30 last year, the Syrian Observatory for Human Rights said.

More than 1,700 civilians have been killed in Syria since Russia began air strikes. In Picture: A man sprays water on an ambulance at a site hit by what activists said were three consecutive airstrikes carried out by the Russian air force on Jan. 12, 2016.Reuters

More than 4,000 people, including 1,733 civilians, have been killed in Syria five months since Russia began conducting air strikes in the country on Sept. 30 last year, the Syrian Observatory for Human Rights said.

Russia began carrying out air strikes on the request of Syrian President Bashar al-Assad, but the United States has accused it of targeting West-backed rebel groups fighting against the regime forces.

Between Sept. 30, 2015 and March 1, 2016, 4,408 people were killed in air strikes and missile strikes in Syria, including 1,173 civilians, the UK-based monitoring agency said in a report Thursday. The casualties included more than 400 children and 250 women.

However, the Russian air strikes also killed more than 1,100 militants of the Islamic State group, SOHR said. Nearly 1,500 members of rebel groups as well as of Al-Qaeda-link Jabhat al Nusra Front were also killed in the air strikes.